I think they've gotten heavier over the years too, and yet the lap times keep doing down. Granted they have thrown about 5-7% more power at it since its initial release.That's the dry weight of the engine. Wet it's around 370.
I was always curious as to why the GTR engine is so heavy. That 3800lb curb weight with all that aluminum and carbon composite in the frame is crazy. Even more ridiculous is how competitive it still is at that weight all these years later